Self Synchronizing Data Communication Method and Device

1. A method comprising: detecting a first change of a physical property of a signal; starting a measurement of a duration of a first time interval that begins with the detection of the first change; detecting a second change of the physical property; stopping the measurement of the duration of the first time interval and starting a second measurement of a duration of a second time interval in response to the detection of the second change; detecting a third change of the physical property, and stopping the second measurement in response to detecting the third change; determining a relation of the durations of the first time interval and the second time interval from the first measurement and the second measurement; and determining the received data value based on the determined relation of the durations of the first time interval and the second time interval.

2. The method according to claim 1 , wherein the physical property a supply voltage or supply current, respectively.

3. The method according to claim 1 , wherein the first, second, and third changes of the physical property comprise at least one of: a change of a voltage, a change of an electrical current, a change of an amplitude, a change of a frequency, a change of a phase, and a change of a polarisation.

4. The method according to claim 1 , wherein the method further comprises a transmission of a response signal, comprising: setting a duration of a third time interval subsequent to the second time interval based on the duration of at least one of the first time interval and the second time interval; and transmitting the response signal during the third time interval.

5. The method according to claim 4 , wherein transmitting the response signal comprises controlling, as a function of a response data value to be transmitted, at least one of a voltage, an electrical current, an amplitude, a frequency, a phase, and a polarization during at least a portion of the third time interval.

6. The method according to claim 4 , wherein the response signal is formed by controlling an electrical current on a same electrical connection as a voltage to a first magnitude in case a first response value is to be transmitted during the third time interval, and by alternatively controlling the electrical current to a second magnitude in case a second response value is to be transmitted during the third time interval, wherein the voltage corresponds to the physical property of the signal that exhibit's the first, second, and third changes.

7. The method according to claim 4 , wherein the reception of a sequence of data values and the transmission of a sequence of response signals are performed in an alternating manner for the sequence of data values and the sequence of response signals.

8. The method according to claim 7 , further comprising a pause interval between the transmission of one of response signals and the reception of a subsequent one of data values.

9. The method according to claim 1 , further comprising: assessing on the basis of at least one of the first measurement and the second measurement whether an observed pattern of changes of the physical property corresponds to a first data transmission protocol or a second data transmission protocol; and performing the action of determining the data value only in case the observed pattern of changes of the physical property corresponds to the first data transmission protocol.

10. The method according to claim 9 , further comprising: switching an operating mode of a component performing the method to the first data transmission protocol or to the second data transmission protocol depending on whether the observed pattern of changes of the physical property corresponds to the first data transmission protocol or the second data transmission protocol, respectively.

11. The method according to claim 1 , further comprising: buffering data values that have been received to maintain a sequence of recently received data values; comparing the sequence of recently received data values with at least one handshake pattern; and switching an operating mode regarding a data transmission protocol of a component performing the method depending on whether the sequence of recently received data values is equal to one of the at least one handshake pattern.

12. The method according to claim 1 , further comprising: assessing whether a transmission channel on which the physical property is observed is requested by a different data transmission protocol; and switching to an alternative transmission channel for conducting the data transmission if the transmission channel is requested by the different data transmission protocol.

13. The method according to claim 1 , wherein the data transmission occurs via a bus topology having at least three components connected to it, wherein identifying an individual component uses at least one of a unique electrical behavior of each individual component, a unique Bus-ID set up individually for each individual component, and a unique device number, combined with an arbitration scheme.

14. The method according to claim 1 , further comprising: receiving a polling request from a remote component; determining whether data to be transmitted to the remote component is available; and transmitting a positive response to the polling request to the remote component during a third time interval subsequent to the second time interval if data to be transmitted is available.

15. The method according to claim 14 , wherein the data transmission occurs via a bus topology having at least three components connected to it, the method further comprising: comparing an incoming data transmission from the remote component with a unique Bus-ID or a unique device number; and if a portion of the incoming data transmission matches the unique Bus-ID or the unique device number, sending the data to be transmitted to the remote component in a plurality of subsequent data transmission cycles.

16. A method comprising: performing, at a first component, at least three change events regarding a quantity on a physical connection to a remote component, wherein a forward data value to be transmitted from the first component to a second component is indicated by a relative timing of one of the change events among the at least three change events; and responding, at the second component, by controlling another quantity of the physical connection depending on a backward data value to be transmitted from the second component to the first component subsequent to one of the change events of the at least three change events.

17. A data communication device comprising: a terminal to connect the data communication device to a remote data communication device via a transmission channel; a detector to detect changes of a physical property on the transmission channel; a circuit to receive a change information from the detector enabling a determination of a relation of a duration of a first time interval and of a duration of a second time interval of a pulse width modulation cycle defined by at least three change events regarding the physical property, the circuit being further configured to determine a time interval relation information based on relative durations of the first time interval and the second time interval; and a data value provider to provide a data value transmitted to the data communication device via the transmission channel based on the determined time interval relation information.

18. The data communication device according to claim 17 , further comprising: a controllable source configured to control another physical property on the transmission channel depending on a backward data value to be transmitted to the remote component during a third time interval subsequent to the second time interval.

19. The data communication device according to claim 18 , wherein the controllable source is configured to control at least one of a magnitude, a frequency, a phase, and a polarization of the other physical property so that it has a specific value at a reading time instant during the third time interval, the specific value being indicative of the backward value to be transmitted.

20. The data communication device according to claim 18 , wherein the controllable source is configured to cause, depending on the backward data value to be transmitted, a leading edge or a trailing edge with respect to the other physical property during the third time interval.

21. The data communication device according to claim 17 , wherein the terminal is a supply terminal of the data communication device or of a device comprising the data communication device, wherein the physical property is a supply voltage or a supply current and the data communication to the data communication device is performed by modulating the supply voltage or the supply current to cause the changes of the physical property.

22. The data communication device according to claim 21 , wherein the data communication device is configured to influence a magnitude of the electrical supply current on the electrical connection to perform a data communication from the data communication device to a remote data communication device.

23. The data communication device according to claim 17 , wherein the physical property can change between at least two levels.

24. The data communication device according to claim 17 , further comprising an identification unit configured to store an identifier for the data communication device that may be used when the data communication device is used in a bus configuration, wherein the identification unit is further configured to compare an incoming sequence of data values with the identifier and to cause a change of an operating mode of the data communication device if the incoming sequence matches the identifier.

25. The data communication device according to claim 17 , further comprising: a second terminal to connect the data communication device to the remote data communication device via another transmission channel; a switching element connected to the second terminal and configured to modulate the physical property or another physical property on the transmission channel; and a multiplexer configured to multiplex the terminal and the second terminal for being connected to the detector based on a multiplexer control signal that controls whether the data communication is to occur via the transmission channel or the other transmission channel.